Continued efforts will be towards the perfection of a method for the quantitative determination of hydroxypropylcellulose (Klucel) in the presence of methylcellulose and hydroxypropylmethylcellulose. Mixtures will be treated with 10 percent NaCl in which Klucel will be salted out. The precipitated Klucel will be trapped on a Celite Column, deluted with cold water and the quantity present assayed by the Phenol-H2SO4 reagent. Better procedures will be sought for the isolation of Klucel from foods with a high fat content. Also, the difficulty of obtaining good recovery of Klucel with a molar substitution of 3.1 will be studied in detail. All three cellulose ethers will be treated with H2SO4 of increasing concentrations at temperatures of 40 degrees C to boiling temperature. Differences in color development will be noted and exploited for possible differentiation between them. Finally, H2SO4 reagents, particularly H2SO4-tannin mixtures, will be used to possibly differentiate between and determine quantitatively these cellulose ethers.